The following patents and other publications are believed to represent the current state of the art:
U.S. patent application Ser. No. 09/283,598 of Kipnis et al, filed 1 Apr. 1999, and corresponding published UK Patent Application 2,351,891;
U.S. patent application Ser. No. 09/285,214 of Richardson et al, filed 1 Apr. 1999, and corresponding published UK Patent Application 2,348,530;
a product called SQUID WEB PROXY CACHE, described at World Wide Web site www.squid.org;
an article by Steve Epstein et al, entitled “Macro and Micro Scheduling”, published in NDS Technical Disclosure Bulletin, vol. 1, number 1, September 1999, at pages 6-8; and
the following RFC documents, available at World Wide Web site www.ietf.org:
1. RFC 1945, entitled “Hypertext Transfer Protocol—HTTP/1.0”, dated May 1996.
2. RFC 2186, entitled “Internet Cache Protocol (ICP), version 2”, dated September 1997.
3. RFC 2187, entitled “Application of Internet Cache Protocol (ICP), version 2”, dated September 1997.
The disclosures of all references mentioned above and throughout the present specification are hereby incorporated herein by reference.